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/*
* Copyright 2018 The Hafnium Authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* https://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "hf/arch/vm/power_mgmt.h"
#include "hf/static_assert.h"
#include "vmapi/hf/call.h"
#include "psci.h"
#include "smc.h"
/**
* Starts the CPU with the given ID. It will set the stack pointer according to
* the provided `state` and jump to the entry point with the given argument
* specified in it.
*
* Note: The caller of this function must guarantee that the contents of `state`
* do not change until the new CPU has branched to the given entry point, and
* that it was written-back to memory (that it is not waiting in a data cache)
* because the new CPU is started with caching disabled.
*/
bool arch_cpu_start(uintptr_t id, struct arch_cpu_start_state *state)
{
void vm_cpu_entry(uintptr_t arg);
struct ffa_value smc_res;
/* Try to start the CPU. */
smc_res = smc64(PSCI_CPU_ON, id, (uintptr_t)&vm_cpu_entry,
(uintptr_t)state, 0, 0, 0, SMCCC_CALLER_HYPERVISOR);
return smc_res.func == PSCI_RETURN_SUCCESS;
}
/**
* Stops the current CPU.
*/
noreturn void arch_cpu_stop(void)
{
smc32(PSCI_CPU_OFF, 0, 0, 0, 0, 0, 0, SMCCC_CALLER_HYPERVISOR);
for (;;) {
/* This should never be reached. */
}
}
static_assert(POWER_STATUS_ON == PSCI_RETURN_ON,
"power_status enum values must match PSCI return values.");
static_assert(POWER_STATUS_OFF == PSCI_RETURN_OFF,
"power_status enum values must match PSCI return values.");
static_assert(POWER_STATUS_ON_PENDING == PSCI_RETURN_ON_PENDING,
"power_status enum values must match PSCI return values.");
/**
* Returns the power status of the given CPU.
*/
enum power_status arch_cpu_status(cpu_id_t cpu_id)
{
uint32_t lowest_affinity_level = 0;
struct ffa_value smc_res;
/*
* This works because the power_status enum values happen to be the same
* as the PSCI_RETURN_* values. The static_asserts above validate that
* this is the case.
*/
smc_res = smc32(PSCI_AFFINITY_INFO, cpu_id, lowest_affinity_level, 0, 0,
0, 0, SMCCC_CALLER_HYPERVISOR);
return smc_res.func;
}
/**
* Shuts down the system or exits emulation.
*/
noreturn void arch_power_off(void)
{
smc32(PSCI_SYSTEM_OFF, 0, 0, 0, 0, 0, 0, SMCCC_CALLER_HYPERVISOR);
for (;;) {
/* This should never be reached. */
}
}
/**
* Restarts the system.
*/
noreturn void arch_reboot(void)
{
smc32(PSCI_SYSTEM_RESET, 0, 0, 0, 0, 0, 0, SMCCC_CALLER_HYPERVISOR);
for (;;) {
/* This should never be reached. */
}
}